Location: Mendenhall Ice Caves

Back to the "23 Unbelievable Places" set.


Description: The ice forms a massive cavern. Everything in your vision is tinted an eerily pale blue, and the light plays off the ice formations. The air is frigid, and all the warmth from your body is sapped out just by being here. You can hear the faint sounds of the water surrounding the cavern, muffled through the thick walls of ice. You slip slightly while you walk, your feet unable to find sure purchase on the floors of the ice. The caves twist and turn about, sometimes seeming random and natural, but other times appearing as though constructed by an architect. The ice bubbles out in some places, with smooth and even shells, and at other points is jagged and rough. 

Associated Knowledges:
Nature:

• These caves are only possible due to the freezing temperatures far beneath the sea.
• The caves were formed naturally, at least in part.
• The caves are home to many creatures who thrive in these temperatures.

Arcana:

• A faint magical aura permeates the caves entirely.
• Parts of the cave were shaped by magical means long ago.
• The caves have been enchanted to be ever-growing deeper into the ocean.

Planes:

• The upper levels of the caves are grounded in the Material Plane.
• The caves seem to bend towards the Elemental Plane of Ice.
• The caves are a connection between the Material Plane and the Elemental Plane of Ice, and a skilled magician could open a gate between the two from the depths of the cave.

DM Info:
  The Mendenhall Ice Caves are an ancient ice structure beneath the sea. Long ago they were formed naturally, but were discovered by a group of wizards who wanted to study the Elemental Plane of Ice. The caves became their place of research, and were shaped by the wizards so they could perform experiments. Over time, the caves have been inhabited by numerous other creatures, mostly frost giants or other denizens of the Elemental Plane of Ice. Arctic Druids have also taken up residence in the halls at least once, feeling that it was especially close to nature. Mindless creatures have also lived there, either deep-sea fish or other entities. Demons and devils have also lived in the caves, as they don't really care about the environment and it provided a good spot to hide away from those that would do them harm.
  The caves are, for the most part, not terribly dangerous in and of themselves. The only difficulties the PCs should have from the caves are the slippery floors and cold temperatures. Some areas of the caves may have been enchanted so as to be more habitable by some of the people who have lived here before, but that magic could have worn off over time. The caves were constructed mostly naturally, and so emulate a more natural pattern in the tunnels. Generally, they grow mostly in a downward direction, and the attunement to the Elemental Plane of Ice gets stronger the deeper it goes. This is mostly harmless to the PCs, but more powerful creatures would be more likely to live in those deeper areas. 
  Encounters inside the caves should almost definitely include copious amounts of difficult terrain. The ice was never really meant for combat to take place inside of it, and the PCs are likely to be the only things in there that aren't naturally adapted to this environment. The slippery ice I would imagine would act as though a Grease spell had been cast on that area, in addition to other difficult terrain just from the formation of the floor. If the fighting is too rough, sections of the caves could also collapse, causing temporary floods. This would make fights in the cave far more brutal, but also allow for a dramatic escape sequence from the collapsing and flooding caves. 
  Even just getting to the Mendenhall Ice Caves should not be easy. They are, after all, far underwater. Different parties may have different approaches to entering the caves. For instance, a party with a Druid would have an easier time casting spells that would make the party able to access the caves. A party with an Artificer might construct a makeshift submarine. Go nuts.
  The caves can be as large or as small as you want. The way I envision them is to actually have them be constantly growing downwards and outwards. The upper "floors" would be fairly narrow, while the lower the PCs descend, the wider and more complex the levels will become. Perhaps even to the point that an entire ice city could be present very far down, or that warring factions could exist between the different levels. A possible breakdown that I am considering:

• The upper floors would be nearly uninhabited, and the PCs would only contend with the natural challenges of the caves themselves.
• After a few levels down, the PCs may encounter some random wildlife. Winter Wolves, Wargs, small elementals.
• Towards the intermediate levels, the PCs find that a group of Frost Goblins have made their home spanning a few levels. Their boss is on the bottom level (of course), and they are forced to fight their way through.
• Lower down, there are three massive levels to the ice caves, each one essentially constituting it's own fortress. On each level are warring factions.
• A Frost Giant jarl has mustered his tribesmen from the Elemental Plane of Ice and wants to control the caves. He doesn't know that the surface world isn't as cold as he'd like.
• An Ice Devil wants this place as his own personal lair to begin the conquest of the Material Plane. He has summoned a number of smaller devils, and bound a number of Frost Goblins to his will.
• A group of Aboleth are enslaving anything and everything they can find, and also hope to own the caves. They actually have a number of Skum in addition to enslaved members of the other warring factions. 
• A Mind Flayer is also trying to take control. He is the only one not entirely suited to the climate, but appreciates the caves for the security as a lair. He is summoning armies of aberrations.
• Even lower still, the PCs can possibly be outright transported to the Elemental Plane of Ice, or move between the planes fluidly.

Adventure Hooks:

• A wizard knows that long ago, other magi used the caverns for their research. He wishes to continue this research, and employs the PCs to help him find and secure the caves for his own purposes.
• People in the fishing villages are going missing. The PCs investigate to find that they are being taken by merfolk slavers into the caves.
• The mysterious ice caverns suddenly emerge from the depths up to the surface. The PCs investigate.